Thermal treatment of biomass, comprises e.g. indirect drying of biomass, obtaining heating steam by compressing dried steam vapor escaping from biomass, supplying heating steam in heating tube of drying apparatus and condensing

摘要

Thermal treatment of biomass by drying and/or embrittling, comprises: indirect drying of biomass; obtaining the heating steam by compressing a dried steam vapor escaping from the biomass; supplying the heating steam in a heating tube of the drying apparatus and condensing; discharging the heated steam condensate (4); removing the dried steam vapor escaping from the biomass and supplying to the compressor; supplying dried biomass in another directly or indirectly acting apparatus and heating with a recycle gas (8); and using the gases debound in the thermal treatment for heating recycle gas. Thermal treatment of biomass by drying and/or embrittling, comprises: indirect drying of biomass with a heating steam (17) in a drying apparatus (13) with internal heater elements at temperatures up to 145[deg] C, preferably up to 120[deg] C; obtaining the heating steam by compressing a dried steam vapor escaping from the biomass at pressures up to 0.4 MPa (4 bar), preferably up to 0.1 MPa (1 bar); supplying the heating steam in a heating tube of the drying apparatus and condensing by heat transfer to the biomass; discharging the heated steam condensate (4) from the drying apparatus; removing the dried steam vapor escaping from the biomass and supplying to the compressor; supplying 80-120[deg] C hot dried biomass in another directly or indirectly acting apparatus for thermal treatment (14) and heating to a temperatures of 250-600[deg] C, preferably 280-320[deg] C with a recycle gas (8) as a fuel gas; and using the gases debound in the thermal treatment for heating the recycle gas. An independent claim is also included for an arrangement for thermal treatment of biomass, comprising the drying apparatus with internal heating steam-traversed heating elements for indirect drying of biomass at temperatures of 145[deg] C, preferably up to 120[deg] C, to a water content of 10 mass-%, a separator for separating solids from vapor, which are fed to the drying apparatus, the compressor for compressing the vapor to heating steam with a pressure of up to 0.4 MPa (4 bar), preferably to 0.1 MPa (1 bar) to form a heating steam circulation, the drying apparatus comprising an outlet for heating steam condensate, which is obtained by heat transfer to the biomass, the 80-120[deg] C hot from dried biomass from the drying apparatus is led to the apparatus for the thermal treatment and heating to a temperature of 250-600[deg] C, preferably 280-320[deg] C, and a gas circuit, in which the gases debound in the apparatus for thermal treatment of the biomass is led to the combustion chamber and the recycle gas of the combustion chamber is led to the apparatus for thermal treatment.